mail_queue_check_vm_interval — how often to apply memory management reduction on mail queues
mail_queue_check_vm_interval = 60
How often to apply memory management reduction on mail queues, based on the configured memory utilization limits.
By default, the system checks once a minute to see if too much memory is being used and attempts to swap out messages from the queues if usage is excessive.
The default value for this option is
mail_queue_check_vm_interval is valid in the global scope.